Images

Herb, regarding your posted intake size, is that an overall diameter, or a corrected figure allowing for the shock cone?
I had wondered about a modification to the stock intake that would place the cone further in, thereby reducing it's diameter and influence on the ducting, possibly reducing or eliminating the cheater.
Quite a bit of work I'm sure, but still scale, as the full scale cone would move for and aft as required.

Edit...
Looking closer to your images, I see the large restriction created by the central diverter that houses the cockpit area(similar to a MiG15)
I don't imagine there is much to do about that

On my large MiG-21 I carved out the shock cone from the bottom, inside :

The whole nose / intake part there is a lot more aerodynamically clean, I think.

But, as you say, I doubt that the cheater intake can be eliminated on this one ...

The ducting design around the battery box on the Freewing one is well made, they used ply sides to allow as much air as possible to
flow through. As I said, the worst part is the rounded rear of the green shockcone.

There seem to be numerous reports on Freewing servo failures, esp. the flap ones. Which seems rather odd since, just like in the case of the "blue box", I never had a Freewing servo fail myself.

Note in particular, from the picture of my MiG-21 below, that there is nothing special about these Freewing flap servos, they are just like all the other ones, standard (metal gear?) 9g digital servos.

I have an alternative explanation: There is one unique feature of flap servos - on these or any other Freewing edf jet. If the linkage adjustment of the flap servo is done incorrectly, the servo gets stalled when the flap is up (retracted). This draws quite a bit of extra current and heats the servo up over time, until it fails and possibly brings the plane down. This is particularly true of digital servos.

It is therefore essential to carefully adjust the linkages & throws on the flaps so that there is absolutely no binding.

EDIT: Note incidentally that the above linked MiG-21 spare parts list from MRC is inconsistent with the servo list added below. The former lists a mix of plastic gear analog servos, plastic gear digital servos, and metal gear digital servos, some of them reversed. On the other hand the list below (from the MiG-21 product page at MRC) list digital metal gear servos exclusively. So there might have been some design changes along the way? I wish I knew what type of servo mine has in it.